[GRASS-user] Splitting lines by other lines that overlap

Markus Metz markus.metz.giswork at gmail.com
Mon Mar 2 12:42:25 PST 2020

Hi Johannes,

On Fri, Feb 28, 2020 at 4:27 PM Johannes Radinger <
johannesradinger at gmail.com> wrote:
> Hi all,
> I have two line vectors: LV1) a complete stream network LV2) sections of
the same stream network representing impoundments.
> LV2 is a subset of LV1 and fully spatially overlapping. However, the full
stream network consists of polylines with start/end nodes that do not
correspond to the impoundments vector:
> LV1 (complete network):
> +-------------------+------------------+
> LV2 (subset with different start/end nodes)
>      +---+               +-------------+
> So how can I get the information of impoundments (LV2) into the attribute
table of the first line vector (LV1). A way that came into my mind but
which is somehow cumbersome:
> 1) Extract the start/end node coordinates each impoundment (LV2) using
> 2) Use these coordinates in v.edit to break the river network (LV1)
> 3) Add new categories in layer 2 of LV1 and add an attribute table
> 4) Use v.distance to query the information from LV2 and copy it to the
corresponding new reaches in LV1
> ..This is not yet tested and not the most straight forward way.
> All this I guess would be easier if there would be something like
v.overlay that works with two line vectors...

The only alternative I can think of is v.clean tool=break errors=nodes, but
this might not be exactly what you need: start/end nodes from LV2 might be
missing if there are matching nodes in LV1. Your approach seems to be
reasonable, even if it involves several steps.

Markus M

> Has anybody done similar analysis in GRASS so far?
> cheers,
> Johannes
> tart/end nodes of the
> _______________________________________________
> grass-user mailing list
> grass-user at lists.osgeo.org
> https://lists.osgeo.org/mailman/listinfo/grass-user
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/grass-user/attachments/20200302/9e34e5d4/attachment.html>

More information about the grass-user mailing list